Lesbian, gay, and bisexual (LGB) youth and adults suffer disparities in health outcomes compared with their heterosexual peers. Minority stress theory suggests that because of prejudice and stigma in the social environment, LGB people experience excess stress that leads to poor health outcomes and health disparities. Because of its focus on the social environment, minority stress theory leads us to predict that the character of stress processes affecting LGBs shift along with improvement in the social environment. Similarly shifting are notions of LGB identity, connection with the community, and the types of social and health services LGB people seek. If we are to achieve the U.S. Public Health Services' goal of reducing health disparities related to sexual orientation, we need to understand the impact of changes in identity and minority stress on LGB health and, using this knowledge, inform public health interventions across the lifespan. To gain this knowledge, we propose a longitudinal study using a probability sample of diverse LGBs representative of LGBs in the U.S. population. We seek to compare 3 cohorts of LGB individuals-aged 18 - 25, 34 - 42, and 48 - 55 years old-who are distinct in that they were exposed to significantly different social environments when they came of age. We are interested in ways that identity and minority stress predict health across the cohorts. We will use a mixed method design that allows us to gain knowledge from both qualitative and survey data. We use an innovative 2-stage procedure to recruit a sample of 676 LGB individuals representative of U.S. Black, Latino, and White LGB populations. We assess respondents baseline and annually for 3 years thereafter. In a qualitative study, we use a narrative life history to assess a diverse group of Black, Latino, White, and Asian LGB individuals in urban and rural regions of New York, California, and Arizona. We hypothesize that: 1. Despite readily acknowledging an LGB identity and coming out at a younger age than did older cohorts, the younger cohorts differ from older cohorts in that their LGB identity is less central, they are less strongly identified with the LGB community, and have different meanings of sexual orientation and identity. 2. Compared with older, the younger cohort experience less minority stress related to their own acceptance of a gay identity and coming out, but more external stress, including prejudice-related stressful life events, antigay violence, and everyday forms of discrimination. 3. Members of younger LGB cohorts utilize fewer LGB-identified social and health services than do members of older LGB cohorts. 4. In structural equations, the minority stress model functions equally well in predicting health outcomes in the younger and older cohorts, but patterns of stress, resilience, and health outcomes differ among the cohorts in accordance with findings in Aims 1 and 2.